Mine is outdoors 24/7 as well. It is beginning to show it's age after 4 years of use. At only $30 bucks for the whole thing, I'll end up replacing it at some point this summer. I can tell you it lasts a whole lot longer than anything available in the retail market at the typical stores.
I bought a second big tube so I can swap them out in case there is ice that needs to thaw, or if it is raining and I can come inside to measure. I guess it will last twice as long that way!
